parser: fix panic for parse invalid map type (#14431)

vlib/v/parser/parse_type.v

@@ -113,12 +113,12 @@ pub fn (mut p Parser) parse_map_type() ast.Type {
 	}
 	p.check(.lsbr)
 	key_type := p.parse_type()
-	key_sym := p.table.sym(key_type)
-	is_alias := key_sym.kind == .alias
 	if key_type.idx() == 0 {
 		// error is reported in parse_type
 		return 0
 	}
+	key_sym := p.table.sym(key_type)
+	is_alias := key_sym.kind == .alias
 	key_type_supported := key_type in [ast.string_type_idx, ast.voidptr_type_idx]
 		|| key_sym.kind in [.enum_, .placeholder, .any]
 		|| ((key_type.is_int() || key_type.is_float() || is_alias) && !key_type.is_ptr())

vlib/v/tests/parse_invalid_map_type_test.v

@@ -0,0 +1,13 @@
+import v.ast
+import v.parser
+import v.pref
+
+fn test_parser_map_type() {
+	result := parser.parse_text('a := map[*Node]bool', '', ast.new_table(), .parse_comments,
+		&pref.Preferences{
+		output_mode: .silent
+		is_fmt: true
+	})
+	println(result)
+	assert true
+}